6 files changed, 423 insertions, 178 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 6c99f5037801..98f230f6a28d 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -41,9 +41,13 @@ static DEFINE_RWLOCK(amd_iommu_devtable_lock);
 static LIST_HEAD(iommu_pd_list);
 static DEFINE_SPINLOCK(iommu_pd_list_lock);
 
-#ifdef CONFIG_IOMMU_API
+/*
+ * Domain for untranslated devices - only allocated
+ * if iommu=pt passed on kernel cmd line.
+ */
+static struct protection_domain *pt_domain;
+
 static struct iommu_ops amd_iommu_ops;
-#endif
 
 /*
  * general struct to manage commands send to an IOMMU
@@ -55,16 +59,16 @@ struct iommu_cmd {
 static int dma_ops_unity_map(struct dma_ops_domain *dma_dom,
                              struct unity_map_entry *e);
 static struct dma_ops_domain *find_protection_domain(u16 devid);
-static u64* alloc_pte(struct protection_domain *dom,
-                      unsigned long address, u64
-                      **pte_page, gfp_t gfp);
+static u64 *alloc_pte(struct protection_domain *domain,
+                      unsigned long address, int end_lvl,
+                      u64 **pte_page, gfp_t gfp);
 static void dma_ops_reserve_addresses(struct dma_ops_domain *dom,
                                       unsigned long start_page,
                                       unsigned int pages);
-
-#ifndef BUS_NOTIFY_UNBOUND_DRIVER
-#define BUS_NOTIFY_UNBOUND_DRIVER 0x0005
-#endif
+static void reset_iommu_command_buffer(struct amd_iommu *iommu);
+static u64 *fetch_pte(struct protection_domain *domain,
+                      unsigned long address, int map_size);
+static void update_domain(struct protection_domain *domain);
 
 #ifdef CONFIG_AMD_IOMMU_STATS
 
@@ -138,7 +142,25 @@ static int iommu_has_npcache(struct amd_iommu *iommu)
  *
  ****************************************************************************/
 
-static void iommu_print_event(void *__evt)
+static void dump_dte_entry(u16 devid)
+{
+        int i;
+
+        for (i = 0; i < 8; ++i)
+                pr_err("AMD-Vi: DTE[%d]: %08x\n", i,
+                        amd_iommu_dev_table[devid].data[i]);
+}
+
+static void dump_command(unsigned long phys_addr)
+{
+        struct iommu_cmd *cmd = phys_to_virt(phys_addr);
+        int i;
+
+        for (i = 0; i < 4; ++i)
+                pr_err("AMD-Vi: CMD[%d]: %08x\n", i, cmd->data[i]);
+}
+
+static void iommu_print_event(struct amd_iommu *iommu, void *__evt)
 {
         u32 *event = __evt;
         int type  = (event[1] >> EVENT_TYPE_SHIFT)  & EVENT_TYPE_MASK;
@@ -147,7 +169,7 @@ static void iommu_print_event(void *__evt)
         int flags = (event[1] >> EVENT_FLAGS_SHIFT) & EVENT_FLAGS_MASK;
         u64 address = (u64)(((u64)event[3]) << 32) | event[2];
 
-        printk(KERN_ERR "AMD IOMMU: Event logged [");
+        printk(KERN_ERR "AMD-Vi: Event logged [");
 
         switch (type) {
         case EVENT_TYPE_ILL_DEV:
@@ -155,6 +177,7 @@ static void iommu_print_event(void *__evt)
                        "address=0x%016llx flags=0x%04x]\n",
                        PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid),
                        address, flags);
+                dump_dte_entry(devid);
                 break;
         case EVENT_TYPE_IO_FAULT:
                 printk("IO_PAGE_FAULT device=%02x:%02x.%x "
@@ -176,6 +199,8 @@ static void iommu_print_event(void *__evt)
                 break;
         case EVENT_TYPE_ILL_CMD:
                 printk("ILLEGAL_COMMAND_ERROR address=0x%016llx]\n", address);
+                reset_iommu_command_buffer(iommu);
+                dump_command(address);
                 break;
         case EVENT_TYPE_CMD_HARD_ERR:
                 printk("COMMAND_HARDWARE_ERROR address=0x%016llx "
@@ -209,7 +234,7 @@ static void iommu_poll_events(struct amd_iommu *iommu)
         tail = readl(iommu->mmio_base + MMIO_EVT_TAIL_OFFSET);
 
         while (head != tail) {
-                iommu_print_event(iommu->evt_buf + head);
+                iommu_print_event(iommu, iommu->evt_buf + head);
                 head = (head + EVENT_ENTRY_SIZE) % iommu->evt_buf_size;
         }
 
@@ -296,8 +321,11 @@ static void __iommu_wait_for_completion(struct amd_iommu *iommu)
         status &= ~MMIO_STATUS_COM_WAIT_INT_MASK;
         writel(status, iommu->mmio_base + MMIO_STATUS_OFFSET);
 
-        if (unlikely(i == EXIT_LOOP_COUNT))
-                panic("AMD IOMMU: Completion wait loop failed\n");
+        if (unlikely(i == EXIT_LOOP_COUNT)) {
+                spin_unlock(&iommu->lock);
+                reset_iommu_command_buffer(iommu);
+                spin_lock(&iommu->lock);
+        }
 }
 
 /*
@@ -445,47 +473,78 @@ static void iommu_flush_tlb_pde(struct amd_iommu *iommu, u16 domid)
 }
 
 /*
+ * This function flushes one domain on one IOMMU
+ */
+static void flush_domain_on_iommu(struct amd_iommu *iommu, u16 domid)
+{
+        struct iommu_cmd cmd;
+        unsigned long flags;
+
+        __iommu_build_inv_iommu_pages(&cmd, CMD_INV_IOMMU_ALL_PAGES_ADDRESS,
+                                      domid, 1, 1);
+
+        spin_lock_irqsave(&iommu->lock, flags);
+        __iommu_queue_command(iommu, &cmd);
+        __iommu_completion_wait(iommu);
+        __iommu_wait_for_completion(iommu);
+        spin_unlock_irqrestore(&iommu->lock, flags);
+}
+
+static void flush_all_domains_on_iommu(struct amd_iommu *iommu)
+{
+        int i;
+
+        for (i = 1; i < MAX_DOMAIN_ID; ++i) {
+                if (!test_bit(i, amd_iommu_pd_alloc_bitmap))
+                        continue;
+                flush_domain_on_iommu(iommu, i);
+        }
+
+}
+
+/*
  * This function is used to flush the IO/TLB for a given protection domain
  * on every IOMMU in the system
  */
 static void iommu_flush_domain(u16 domid)
 {
-        unsigned long flags;
         struct amd_iommu *iommu;
-        struct iommu_cmd cmd;
 
         INC_STATS_COUNTER(domain_flush_all);
 
-        __iommu_build_inv_iommu_pages(&cmd, CMD_INV_IOMMU_ALL_PAGES_ADDRESS,
-                                      domid, 1, 1);
-
-        for_each_iommu(iommu) {
-                spin_lock_irqsave(&iommu->lock, flags);
-                __iommu_queue_command(iommu, &cmd);
-                __iommu_completion_wait(iommu);
-                __iommu_wait_for_completion(iommu);
-                spin_unlock_irqrestore(&iommu->lock, flags);
-        }
+        for_each_iommu(iommu)
+                flush_domain_on_iommu(iommu, domid);
 }
 
 void amd_iommu_flush_all_domains(void)
 {
+        struct amd_iommu *iommu;
+
+        for_each_iommu(iommu)
+                flush_all_domains_on_iommu(iommu);
+}
+
+static void flush_all_devices_for_iommu(struct amd_iommu *iommu)
+{
         int i;
 
-        for (i = 1; i < MAX_DOMAIN_ID; ++i) {
-                if (!test_bit(i, amd_iommu_pd_alloc_bitmap))
+        for (i = 0; i <= amd_iommu_last_bdf; ++i) {
+                if (iommu != amd_iommu_rlookup_table[i])
                         continue;
-                iommu_flush_domain(i);
+
+                iommu_queue_inv_dev_entry(iommu, i);
+                iommu_completion_wait(iommu);
         }
 }
 
-void amd_iommu_flush_all_devices(void)
+static void flush_devices_by_domain(struct protection_domain *domain)
 {
         struct amd_iommu *iommu;
         int i;
 
         for (i = 0; i <= amd_iommu_last_bdf; ++i) {
-                if (amd_iommu_pd_table[i] == NULL)
+                if ((domain == NULL && amd_iommu_pd_table[i] == NULL) ||
+                    (amd_iommu_pd_table[i] != domain))
                         continue;
 
                 iommu = amd_iommu_rlookup_table[i];
@@ -497,6 +556,27 @@ void amd_iommu_flush_all_devices(void)
         }
 }
 
+static void reset_iommu_command_buffer(struct amd_iommu *iommu)
+{
+        pr_err("AMD-Vi: Resetting IOMMU command buffer\n");
+
+        if (iommu->reset_in_progress)
+                panic("AMD-Vi: ILLEGAL_COMMAND_ERROR while resetting command buffer\n");
+
+        iommu->reset_in_progress = true;
+
+        amd_iommu_reset_cmd_buffer(iommu);
+        flush_all_devices_for_iommu(iommu);
+        flush_all_domains_on_iommu(iommu);
+
+        iommu->reset_in_progress = false;
+}
+
+void amd_iommu_flush_all_devices(void)
+{
+        flush_devices_by_domain(NULL);
+}
+
 /****************************************************************************
  *
  * The functions below are used the create the page table mappings for
@@ -514,18 +594,21 @@ void amd_iommu_flush_all_devices(void)
 static int iommu_map_page(struct protection_domain *dom,
                           unsigned long bus_addr,
                           unsigned long phys_addr,
-                          int prot)
+                          int prot,
+                          int map_size)
 {
         u64 __pte, *pte;
 
         bus_addr  = PAGE_ALIGN(bus_addr);
         phys_addr = PAGE_ALIGN(phys_addr);
 
-        /* only support 512GB address spaces for now */
-        if (bus_addr > IOMMU_MAP_SIZE_L3 || !(prot & IOMMU_PROT_MASK))
+        BUG_ON(!PM_ALIGNED(map_size, bus_addr));
+        BUG_ON(!PM_ALIGNED(map_size, phys_addr));
+
+        if (!(prot & IOMMU_PROT_MASK))
                 return -EINVAL;
 
-        pte = alloc_pte(dom, bus_addr, NULL, GFP_KERNEL);
+        pte = alloc_pte(dom, bus_addr, map_size, NULL, GFP_KERNEL);
 
         if (IOMMU_PTE_PRESENT(*pte))
                 return -EBUSY;
@@ -538,29 +621,18 @@ static int iommu_map_page(struct protection_domain *dom,
 
         *pte = __pte;
 
+        update_domain(dom);
+
         return 0;
 }
 
 static void iommu_unmap_page(struct protection_domain *dom,
-                             unsigned long bus_addr)
+                             unsigned long bus_addr, int map_size)
 {
-        u64 *pte;
-
-        pte = &dom->pt_root[IOMMU_PTE_L2_INDEX(bus_addr)];
-
-        if (!IOMMU_PTE_PRESENT(*pte))
-                return;
-
-        pte = IOMMU_PTE_PAGE(*pte);
-        pte = &pte[IOMMU_PTE_L1_INDEX(bus_addr)];
+        u64 *pte = fetch_pte(dom, bus_addr, map_size);
 
-        if (!IOMMU_PTE_PRESENT(*pte))
-                return;
-
-        pte = IOMMU_PTE_PAGE(*pte);
-        pte = &pte[IOMMU_PTE_L1_INDEX(bus_addr)];
-
-        *pte = 0;
+        if (pte)
+                *pte = 0;
 }
 
 /*
@@ -615,7 +687,8 @@ static int dma_ops_unity_map(struct dma_ops_domain *dma_dom,
 
         for (addr = e->address_start; addr < e->address_end;
              addr += PAGE_SIZE) {
-                ret = iommu_map_page(&dma_dom->domain, addr, addr, e->prot);
+                ret = iommu_map_page(&dma_dom->domain, addr, addr, e->prot,
+                                     PM_MAP_4k);
                 if (ret)
                         return ret;
                 /*
@@ -670,24 +743,29 @@ static int init_unity_mappings_for_device(struct dma_ops_domain *dma_dom,
  * This function checks if there is a PTE for a given dma address. If
  * there is one, it returns the pointer to it.
  */
-static u64* fetch_pte(struct protection_domain *domain,
-                      unsigned long address)
+static u64 *fetch_pte(struct protection_domain *domain,
+                      unsigned long address, int map_size)
 {
+        int level;
         u64 *pte;
 
-        pte = &domain->pt_root[IOMMU_PTE_L2_INDEX(address)];
+        level =  domain->mode - 1;
+        pte   = &domain->pt_root[PM_LEVEL_INDEX(level, address)];
 
-        if (!IOMMU_PTE_PRESENT(*pte))
-                return NULL;
+        while (level > map_size) {
+                if (!IOMMU_PTE_PRESENT(*pte))
+                        return NULL;
 
-        pte = IOMMU_PTE_PAGE(*pte);
-        pte = &pte[IOMMU_PTE_L1_INDEX(address)];
+                level -= 1;
 
-        if (!IOMMU_PTE_PRESENT(*pte))
-                return NULL;
+                pte = IOMMU_PTE_PAGE(*pte);
+                pte = &pte[PM_LEVEL_INDEX(level, address)];
 
-        pte = IOMMU_PTE_PAGE(*pte);
-        pte = &pte[IOMMU_PTE_L0_INDEX(address)];
+                if ((PM_PTE_LEVEL(*pte) == 0) && level != map_size) {
+                        pte = NULL;
+                        break;
+                }
+        }
 
         return pte;
 }
@@ -727,7 +805,7 @@ static int alloc_new_range(struct amd_iommu *iommu,
                 u64 *pte, *pte_page;
 
                 for (i = 0; i < num_ptes; ++i) {
-                        pte = alloc_pte(&dma_dom->domain, address,
+                        pte = alloc_pte(&dma_dom->domain, address, PM_MAP_4k,
                                         &pte_page, gfp);
                         if (!pte)
                                 goto out_free;
@@ -760,16 +838,20 @@ static int alloc_new_range(struct amd_iommu *iommu,
         for (i = dma_dom->aperture[index]->offset;
              i < dma_dom->aperture_size;
              i += PAGE_SIZE) {
-                u64 *pte = fetch_pte(&dma_dom->domain, i);
+                u64 *pte = fetch_pte(&dma_dom->domain, i, PM_MAP_4k);
                 if (!pte || !IOMMU_PTE_PRESENT(*pte))
                         continue;
 
                 dma_ops_reserve_addresses(dma_dom, i << PAGE_SHIFT, 1);
         }
 
+        update_domain(&dma_dom->domain);
+
         return 0;
 
 out_free:
+        update_domain(&dma_dom->domain);
+
         free_page((unsigned long)dma_dom->aperture[index]->bitmap);
 
         kfree(dma_dom->aperture[index]);
@@ -1009,7 +1091,7 @@ static struct dma_ops_domain *dma_ops_domain_alloc(struct amd_iommu *iommu)
         dma_dom->domain.id = domain_id_alloc();
         if (dma_dom->domain.id == 0)
                 goto free_dma_dom;
-        dma_dom->domain.mode = PAGE_MODE_3_LEVEL;
+        dma_dom->domain.mode = PAGE_MODE_2_LEVEL;
         dma_dom->domain.pt_root = (void *)get_zeroed_page(GFP_KERNEL);
         dma_dom->domain.flags = PD_DMA_OPS_MASK;
         dma_dom->domain.priv = dma_dom;
@@ -1063,6 +1145,41 @@ static struct protection_domain *domain_for_device(u16 devid)
         return dom;
 }
 
+static void set_dte_entry(u16 devid, struct protection_domain *domain)
+{
+        u64 pte_root = virt_to_phys(domain->pt_root);
+
+        pte_root |= (domain->mode & DEV_ENTRY_MODE_MASK)
+                    << DEV_ENTRY_MODE_SHIFT;
+        pte_root |= IOMMU_PTE_IR | IOMMU_PTE_IW | IOMMU_PTE_P | IOMMU_PTE_TV;
+
+        amd_iommu_dev_table[devid].data[2] = domain->id;
+        amd_iommu_dev_table[devid].data[1] = upper_32_bits(pte_root);
+        amd_iommu_dev_table[devid].data[0] = lower_32_bits(pte_root);
+
+        amd_iommu_pd_table[devid] = domain;
+}
+
+/*
+ * If a device is not yet associated with a domain, this function does
+ * assigns it visible for the hardware
+ */
+static void __attach_device(struct amd_iommu *iommu,
+                            struct protection_domain *domain,
+                            u16 devid)
+{
+        /* lock domain */
+        spin_lock(&domain->lock);
+
+        /* update DTE entry */
+        set_dte_entry(devid, domain);
+
+        domain->dev_cnt += 1;
+
+        /* ready */
+        spin_unlock(&domain->lock);
+}
+
 /*
  * If a device is not yet associated with a domain, this function does
  * assigns it visible for the hardware
@@ -1072,27 +1189,16 @@ static void attach_device(struct amd_iommu *iommu,
                           u16 devid)
 {
         unsigned long flags;
-        u64 pte_root = virt_to_phys(domain->pt_root);
-
-        domain->dev_cnt += 1;
-
-        pte_root |= (domain->mode & DEV_ENTRY_MODE_MASK)
-                    << DEV_ENTRY_MODE_SHIFT;
-        pte_root |= IOMMU_PTE_IR | IOMMU_PTE_IW | IOMMU_PTE_P | IOMMU_PTE_TV;
 
         write_lock_irqsave(&amd_iommu_devtable_lock, flags);
-        amd_iommu_dev_table[devid].data[0] = lower_32_bits(pte_root);
-        amd_iommu_dev_table[devid].data[1] = upper_32_bits(pte_root);
-        amd_iommu_dev_table[devid].data[2] = domain->id;
-
-        amd_iommu_pd_table[devid] = domain;
+        __attach_device(iommu, domain, devid);
         write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
 
-       /*
-        * We might boot into a crash-kernel here. The crashed kernel
-        * left the caches in the IOMMU dirty. So we have to flush
-        * here to evict all dirty stuff.
-        */
+        /*
+         * We might boot into a crash-kernel here. The crashed kernel
+         * left the caches in the IOMMU dirty. So we have to flush
+         * here to evict all dirty stuff.
+         */
         iommu_queue_inv_dev_entry(iommu, devid);
         iommu_flush_tlb_pde(iommu, domain->id);
 }
@@ -1119,6 +1225,15 @@ static void __detach_device(struct protection_domain *domain, u16 devid)
 
         /* ready */
         spin_unlock(&domain->lock);
+
+        /*
+         * If we run in passthrough mode the device must be assigned to the
+         * passthrough domain if it is detached from any other domain
+         */
+        if (iommu_pass_through) {
+                struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
+                __attach_device(iommu, pt_domain, devid);
+        }
 }
 
 /*
@@ -1164,6 +1279,8 @@ static int device_change_notifier(struct notifier_block *nb,
         case BUS_NOTIFY_UNBOUND_DRIVER:
                 if (!domain)
                         goto out;
+                if (iommu_pass_through)
+                        break;
                 detach_device(domain, devid);
                 break;
         case BUS_NOTIFY_ADD_DEVICE:
@@ -1292,39 +1409,91 @@ static int get_device_resources(struct device *dev,
         return 1;
 }
 
+static void update_device_table(struct protection_domain *domain)
+{
+        unsigned long flags;
+        int i;
+
+        for (i = 0; i <= amd_iommu_last_bdf; ++i) {
+                if (amd_iommu_pd_table[i] != domain)
+                        continue;
+                write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+                set_dte_entry(i, domain);
+                write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+        }
+}
+
+static void update_domain(struct protection_domain *domain)
+{
+        if (!domain->updated)
+                return;
+
+        update_device_table(domain);
+        flush_devices_by_domain(domain);
+        iommu_flush_domain(domain->id);
+
+        domain->updated = false;
+}
+
 /*
- * If the pte_page is not yet allocated this function is called
+ * This function is used to add another level to an IO page table. Adding
+ * another level increases the size of the address space by 9 bits to a size up
+ * to 64 bits.
  */
-static u64* alloc_pte(struct protection_domain *dom,
-                      unsigned long address, u64 **pte_page, gfp_t gfp)
+static bool increase_address_space(struct protection_domain *domain,
+                                   gfp_t gfp)
+{
+        u64 *pte;
+
+        if (domain->mode == PAGE_MODE_6_LEVEL)
+                /* address space already 64 bit large */
+                return false;
+
+        pte = (void *)get_zeroed_page(gfp);
+        if (!pte)
+                return false;
+
+        *pte             = PM_LEVEL_PDE(domain->mode,
+                                        virt_to_phys(domain->pt_root));
+        domain->pt_root  = pte;
+        domain->mode    += 1;
+        domain->updated  = true;
+
+        return true;
+}
+
+static u64 *alloc_pte(struct protection_domain *domain,
+                      unsigned long address,
+                      int end_lvl,
+                      u64 **pte_page,
+                      gfp_t gfp)
 {
         u64 *pte, *page;
+        int level;
 
-        pte = &dom->pt_root[IOMMU_PTE_L2_INDEX(address)];
+        while (address > PM_LEVEL_SIZE(domain->mode))
+                increase_address_space(domain, gfp);
 
-        if (!IOMMU_PTE_PRESENT(*pte)) {
-                page = (u64 *)get_zeroed_page(gfp);
-                if (!page)
-                        return NULL;
-                *pte = IOMMU_L2_PDE(virt_to_phys(page));
-        }
+        level =  domain->mode - 1;
+        pte   = &domain->pt_root[PM_LEVEL_INDEX(level, address)];
 
-        pte = IOMMU_PTE_PAGE(*pte);
-        pte = &pte[IOMMU_PTE_L1_INDEX(address)];
+        while (level > end_lvl) {
+                if (!IOMMU_PTE_PRESENT(*pte)) {
+                        page = (u64 *)get_zeroed_page(gfp);
+                        if (!page)
+                                return NULL;
+                        *pte = PM_LEVEL_PDE(level, virt_to_phys(page));
+                }
 
-        if (!IOMMU_PTE_PRESENT(*pte)) {
-                page = (u64 *)get_zeroed_page(gfp);
-                if (!page)
-                        return NULL;
-                *pte = IOMMU_L1_PDE(virt_to_phys(page));
-        }
+                level -= 1;
 
-        pte = IOMMU_PTE_PAGE(*pte);
+                pte = IOMMU_PTE_PAGE(*pte);
 
-        if (pte_page)
-                *pte_page = pte;
+                if (pte_page && level == end_lvl)
+                        *pte_page = pte;
 
-        pte = &pte[IOMMU_PTE_L0_INDEX(address)];
+                pte = &pte[PM_LEVEL_INDEX(level, address)];
+        }
 
         return pte;
 }
@@ -1344,10 +1513,13 @@ static u64* dma_ops_get_pte(struct dma_ops_domain *dom,
 
         pte = aperture->pte_pages[APERTURE_PAGE_INDEX(address)];
         if (!pte) {
-                pte = alloc_pte(&dom->domain, address, &pte_page, GFP_ATOMIC);
+                pte = alloc_pte(&dom->domain, address, PM_MAP_4k, &pte_page,
+                                GFP_ATOMIC);
                 aperture->pte_pages[APERTURE_PAGE_INDEX(address)] = pte_page;
         } else
-                pte += IOMMU_PTE_L0_INDEX(address);
+                pte += PM_LEVEL_INDEX(0, address);
+
+        update_domain(&dom->domain);
 
         return pte;
 }
@@ -1409,7 +1581,7 @@ static void dma_ops_domain_unmap(struct amd_iommu *iommu,
         if (!pte)
                 return;
 
-        pte += IOMMU_PTE_L0_INDEX(address);
+        pte += PM_LEVEL_INDEX(0, address);
 
         WARN_ON(!*pte);
 
@@ -1988,19 +2160,47 @@ static void cleanup_domain(struct protection_domain *domain)
         write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
 }
 
-static int amd_iommu_domain_init(struct iommu_domain *dom)
+static void protection_domain_free(struct protection_domain *domain)
+{
+        if (!domain)
+                return;
+
+        if (domain->id)
+                domain_id_free(domain->id);
+
+        kfree(domain);
+}
+
+static struct protection_domain *protection_domain_alloc(void)
 {
         struct protection_domain *domain;
 
         domain = kzalloc(sizeof(*domain), GFP_KERNEL);
         if (!domain)
-                return -ENOMEM;
+                return NULL;
 
         spin_lock_init(&domain->lock);
-        domain->mode = PAGE_MODE_3_LEVEL;
         domain->id = domain_id_alloc();
         if (!domain->id)
+                goto out_err;
+
+        return domain;
+
+out_err:
+        kfree(domain);
+
+        return NULL;
+}
+
+static int amd_iommu_domain_init(struct iommu_domain *dom)
+{
+        struct protection_domain *domain;
+
+        domain = protection_domain_alloc();
+        if (!domain)
                 goto out_free;
+
+        domain->mode    = PAGE_MODE_3_LEVEL;
         domain->pt_root = (void *)get_zeroed_page(GFP_KERNEL);
         if (!domain->pt_root)
                 goto out_free;
@@ -2010,7 +2210,7 @@ static int amd_iommu_domain_init(struct iommu_domain *dom)
         return 0;
 
 out_free:
-        kfree(domain);
+        protection_domain_free(domain);
 
         return -ENOMEM;
 }
@@ -2115,7 +2315,7 @@ static int amd_iommu_map_range(struct iommu_domain *dom,
         paddr &= PAGE_MASK;
 
         for (i = 0; i < npages; ++i) {
-                ret = iommu_map_page(domain, iova, paddr, prot);
+                ret = iommu_map_page(domain, iova, paddr, prot, PM_MAP_4k);
                 if (ret)
                         return ret;
 
@@ -2136,7 +2336,7 @@ static void amd_iommu_unmap_range(struct iommu_domain *dom,
         iova  &= PAGE_MASK;
 
         for (i = 0; i < npages; ++i) {
-                iommu_unmap_page(domain, iova);
+                iommu_unmap_page(domain, iova, PM_MAP_4k);
                 iova  += PAGE_SIZE;
         }
 
@@ -2151,21 +2351,9 @@ static phys_addr_t amd_iommu_iova_to_phys(struct iommu_domain *dom,
         phys_addr_t paddr;
         u64 *pte;
 
-        pte = &domain->pt_root[IOMMU_PTE_L2_INDEX(iova)];
-
-        if (!IOMMU_PTE_PRESENT(*pte))
-                return 0;
-
-        pte = IOMMU_PTE_PAGE(*pte);
-        pte = &pte[IOMMU_PTE_L1_INDEX(iova)];
-
-        if (!IOMMU_PTE_PRESENT(*pte))
-                return 0;
-
-        pte = IOMMU_PTE_PAGE(*pte);
-        pte = &pte[IOMMU_PTE_L0_INDEX(iova)];
+        pte = fetch_pte(domain, iova, PM_MAP_4k);
 
-        if (!IOMMU_PTE_PRESENT(*pte))
+        if (!pte || !IOMMU_PTE_PRESENT(*pte))
                 return 0;
 
         paddr  = *pte & IOMMU_PAGE_MASK;
@@ -2191,3 +2379,46 @@ static struct iommu_ops amd_iommu_ops = {
         .domain_has_cap = amd_iommu_domain_has_cap,
 };
 
+/*****************************************************************************
+ *
+ * The next functions do a basic initialization of IOMMU for pass through
+ * mode
+ *
+ * In passthrough mode the IOMMU is initialized and enabled but not used for
+ * DMA-API translation.
+ *
+ *****************************************************************************/
+
+int __init amd_iommu_init_passthrough(void)
+{
+        struct pci_dev *dev = NULL;
+        u16 devid, devid2;
+
+        /* allocate passthroug domain */
+        pt_domain = protection_domain_alloc();
+        if (!pt_domain)
+                return -ENOMEM;
+
+        pt_domain->mode |= PAGE_MODE_NONE;
+
+        while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
+                struct amd_iommu *iommu;
+
+                devid = calc_devid(dev->bus->number, dev->devfn);
+                if (devid > amd_iommu_last_bdf)
+                        continue;
+
+                devid2 = amd_iommu_alias_table[devid];
+
+                iommu = amd_iommu_rlookup_table[devid2];
+                if (!iommu)
+                        continue;
+
+                __attach_device(iommu, pt_domain, devid);
+                __attach_device(iommu, pt_domain, devid2);
+        }
+
+        pr_info("AMD-Vi: Initialized for Passthrough Mode\n");
+
+        return 0;
+}
diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index c1b17e97252e..b4b61d462dcc 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -252,7 +252,7 @@ static void __init iommu_feature_disable(struct amd_iommu *iommu, u8 bit)
 /* Function to enable the hardware */
 static void iommu_enable(struct amd_iommu *iommu)
 {
-        printk(KERN_INFO "AMD IOMMU: Enabling IOMMU at %s cap 0x%hx\n",
+        printk(KERN_INFO "AMD-Vi: Enabling IOMMU at %s cap 0x%hx\n",
                dev_name(&iommu->dev->dev), iommu->cap_ptr);
 
         iommu_feature_enable(iommu, CONTROL_IOMMU_EN);
@@ -435,6 +435,20 @@ static u8 * __init alloc_command_buffer(struct amd_iommu *iommu)
 }
 
 /*
+ * This function resets the command buffer if the IOMMU stopped fetching
+ * commands from it.
+ */
+void amd_iommu_reset_cmd_buffer(struct amd_iommu *iommu)
+{
+        iommu_feature_disable(iommu, CONTROL_CMDBUF_EN);
+
+        writel(0x00, iommu->mmio_base + MMIO_CMD_HEAD_OFFSET);
+        writel(0x00, iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
+
+        iommu_feature_enable(iommu, CONTROL_CMDBUF_EN);
+}
+
+/*
  * This function writes the command buffer address to the hardware and
  * enables it.
  */
@@ -450,11 +464,7 @@ static void iommu_enable_command_buffer(struct amd_iommu *iommu)
         memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET,
                     &entry, sizeof(entry));
 
-        /* set head and tail to zero manually */
-        writel(0x00, iommu->mmio_base + MMIO_CMD_HEAD_OFFSET);
-        writel(0x00, iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
-
-        iommu_feature_enable(iommu, CONTROL_CMDBUF_EN);
+        amd_iommu_reset_cmd_buffer(iommu);
 }
 
 static void __init free_command_buffer(struct amd_iommu *iommu)
@@ -858,7 +868,7 @@ static int __init init_iommu_all(struct acpi_table_header *table)
                 switch (*p) {
                 case ACPI_IVHD_TYPE:
 
-                        DUMP_printk("IOMMU: device: %02x:%02x.%01x cap: %04x "
+                        DUMP_printk("device: %02x:%02x.%01x cap: %04x "
                                     "seg: %d flags: %01x info %04x\n",
                                     PCI_BUS(h->devid), PCI_SLOT(h->devid),
                                     PCI_FUNC(h->devid), h->cap_ptr,
@@ -902,7 +912,7 @@ static int __init iommu_setup_msi(struct amd_iommu *iommu)
 
         r = request_irq(iommu->dev->irq, amd_iommu_int_handler,
                         IRQF_SAMPLE_RANDOM,
-                        "AMD IOMMU",
+                        "AMD-Vi",
                         NULL);
 
         if (r) {
@@ -1150,7 +1160,7 @@ int __init amd_iommu_init(void)
 
 
         if (no_iommu) {
-                printk(KERN_INFO "AMD IOMMU disabled by kernel command line\n");
+                printk(KERN_INFO "AMD-Vi disabled by kernel command line\n");
                 return 0;
         }
 
@@ -1242,22 +1252,28 @@ int __init amd_iommu_init(void)
         if (ret)
                 goto free;
 
-        ret = amd_iommu_init_dma_ops();
+        if (iommu_pass_through)
+                ret = amd_iommu_init_passthrough();
+        else
+                ret = amd_iommu_init_dma_ops();
         if (ret)
                 goto free;
 
         enable_iommus();
 
-        printk(KERN_INFO "AMD IOMMU: device isolation ");
+        if (iommu_pass_through)
+                goto out;
+
+        printk(KERN_INFO "AMD-Vi: device isolation ");
         if (amd_iommu_isolate)
                 printk("enabled\n");
         else
                 printk("disabled\n");
 
         if (amd_iommu_unmap_flush)
-                printk(KERN_INFO "AMD IOMMU: IO/TLB flush on unmap enabled\n");
+                printk(KERN_INFO "AMD-Vi: IO/TLB flush on unmap enabled\n");
         else
-                printk(KERN_INFO "AMD IOMMU: Lazy IO/TLB flushing enabled\n");
+                printk(KERN_INFO "AMD-Vi: Lazy IO/TLB flushing enabled\n");
 
 out:
         return ret;
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index fa80f60e9607..d71c8655905b 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -33,7 +33,14 @@ int no_iommu __read_mostly;
 /* Set this to 1 if there is a HW IOMMU in the system */
 int iommu_detected __read_mostly = 0;
 
-int iommu_pass_through;
+/*
+ * This variable becomes 1 if iommu=pt is passed on the kernel command line.
+ * If this variable is 1, IOMMU implementations do no DMA ranslation for
+ * devices and allow every device to access to whole physical memory. This is
+ * useful if a user want to use an IOMMU only for KVM device assignment to
+ * guests and not for driver dma translation.
+ */
+int iommu_pass_through __read_mostly;
 
 dma_addr_t bad_dma_address __read_mostly = 0;
 EXPORT_SYMBOL(bad_dma_address);
@@ -153,7 +160,7 @@ again:
                 return NULL;
 
         addr = page_to_phys(page);
-        if (!is_buffer_dma_capable(dma_mask, addr, size)) {
+        if (addr + size > dma_mask) {
                 __free_pages(page, get_order(size));
 
                 if (dma_mask < DMA_BIT_MASK(32) && !(flag & GFP_DMA)) {
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index d2e56b8f48e7..98a827ee9ed7 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -190,14 +190,13 @@ static void iommu_full(struct device *dev, size_t size, int dir)
 static inline int
 need_iommu(struct device *dev, unsigned long addr, size_t size)
 {
-        return force_iommu ||
-                !is_buffer_dma_capable(*dev->dma_mask, addr, size);
+        return force_iommu || !dma_capable(dev, addr, size);
 }
 
 static inline int
 nonforced_iommu(struct device *dev, unsigned long addr, size_t size)
 {
-        return !is_buffer_dma_capable(*dev->dma_mask, addr, size);
+        return !dma_capable(dev, addr, size);
 }
 
 /* Map a single continuous physical area into the IOMMU.
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index 71d412a09f30..a3933d4330cd 100644
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -14,7 +14,7 @@
 static int
 check_addr(char *name, struct device *hwdev, dma_addr_t bus, size_t size)
 {
-        if (hwdev && !is_buffer_dma_capable(*hwdev->dma_mask, bus, size)) {
+        if (hwdev && !dma_capable(hwdev, bus, size)) {
                 if (*hwdev->dma_mask >= DMA_BIT_MASK(32))
                         printk(KERN_ERR
                             "nommu_%s: overflow %Lx+%zu of device mask %Lx\n",
@@ -79,12 +79,29 @@ static void nommu_free_coherent(struct device *dev, size_t size, void *vaddr,
         free_pages((unsigned long)vaddr, get_order(size));
 }
 
+static void nommu_sync_single_for_device(struct device *dev,
+                        dma_addr_t addr, size_t size,
+                        enum dma_data_direction dir)
+{
+        flush_write_buffers();
+}
+
+
+static void nommu_sync_sg_for_device(struct device *dev,
+                        struct scatterlist *sg, int nelems,
+                        enum dma_data_direction dir)
+{
+        flush_write_buffers();
+}
+
 struct dma_map_ops nommu_dma_ops = {
-        .alloc_coherent = dma_generic_alloc_coherent,
-        .free_coherent  = nommu_free_coherent,
-        .map_sg         = nommu_map_sg,
-        .map_page       = nommu_map_page,
-        .is_phys        = 1,
+        .alloc_coherent         = dma_generic_alloc_coherent,
+        .free_coherent          = nommu_free_coherent,
+        .map_sg                 = nommu_map_sg,
+        .map_page               = nommu_map_page,
+        .sync_single_for_device = nommu_sync_single_for_device,
+        .sync_sg_for_device     = nommu_sync_sg_for_device,
+        .is_phys                = 1,
 };
 
 void __init no_iommu_init(void)
diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 6af96ee44200..e8a35016115f 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -13,31 +13,6 @@
 
 int swiotlb __read_mostly;
 
-void * __init swiotlb_alloc_boot(size_t size, unsigned long nslabs)
-{
-        return alloc_bootmem_low_pages(size);
-}
-
-void *swiotlb_alloc(unsigned order, unsigned long nslabs)
-{
-        return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
-}
-
-dma_addr_t swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
-{
-        return paddr;
-}
-
-phys_addr_t swiotlb_bus_to_phys(struct device *hwdev, dma_addr_t baddr)
-{
-        return baddr;
-}
-
-int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
-{
-        return 0;
-}
-
 static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
                                         dma_addr_t *dma_handle, gfp_t flags)
 {